A Meta-Analysis of the Lagos State Social Health Insurance Scheme's Impact on Catastrophic Health Expenditure Among Informal Sector Traders in Alimosho Local Government Area, 2016

Catastrophic health expenditure (CHE) remains a critical threat to the financial security of informal sector workers in sub-Saharan Africa. While the Lagos State Social Health Insurance Scheme (LSSHIS) was established to improve financial protection, its specific effect on vulnerable populations such as informal traders requires consolidated evidence. This meta-analysis aimed to synthesise quantitative evidence on the impact of the LSSHIS on the incidence of catastrophic health expenditure among informal sector traders in Alimosho Local Government Area. A systematic search was conducted across major electronic databases for relevant studies. Inclusion criteria encompassed observational or interventional studies reporting CHE incidence among enrolled versus non-enrolled informal traders. Data were extracted using a standardised form. Pooled odds ratios with 95% confidence intervals were calculated using a random-effects model. Heterogeneity was assessed using the I² statistic. The analysis included data from five studies. Enrolment in the LSSHIS was associated with a statistically significant reduction in the odds of experiencing CHE. The pooled analysis indicated that enrolled traders were approximately 40% less likely to face catastrophic health expenditure compared to non-enrolled counterparts. The Lagos State Social Health Insurance Scheme appears to be an effective mechanism for reducing the financial risk of ill health among informal sector traders in this setting, thereby enhancing financial protection. Policy efforts should focus on expanding scheme enrolment through targeted outreach and addressing non-financial barriers to access. Further longitudinal research is needed to assess the scheme’s long-term sustainability and equity impacts. Health insurance, catastrophic expenditure, informal sector, meta-analysis, financial protection, Nigeria This study provides the first synthesised quantitative evidence on the LSSHIS’s effect on catastrophic health expenditure for this key demographic.